Visual C++ :: How To Determine Size Of Allocated Buffer
Dec 9, 2014I use new to allocate a buffer, as follows:
BYTE *p;
p = new BYTE[20];
If I do NOT store the size of the allocated buffer, how to determine the buffer size via p only?
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Visual C++ :: How To Determine If A Buffer Is Freed Or Not
Dec 9, 2014I use new to allocate a buffer, as follows:
BYTE *p;
p = new BYTE[20];
...
delete p;
After p is deleted, if I do NOT assign NULL to p, is there a way to determine whether it has already been freed?
Visual C++ :: How New / Delete Store Internal Info About Allocated Buffer
Dec 9, 2014I am using C++ new/delete operators to allocate/deallocate the buffers. I think for each allocated buffer, there should be an additional info block stores the size and other info about the buffer. How to know more details about this info block? I need to override these two operators and find such an info block is useful to my implementation.
View 3 Replies View RelatedVisual C++ :: Retrieving Size Of Each String In Order To Produce A New Buffer For Concatenated String
Feb 25, 2013What is the efficiency of the two assignments (line 1 and 2), i.e. (function calls, number of copies made, etc), also the Big O notation. I know there are function calls for retrieving the size of each string in order to produce a new buffer for the concatenated string...any difference between line 1 and 2 in terms of efficiency?
String s("Hello");
String t("There");
1. s = s + t;
2. s += t;
C# :: Tcp Socket Buffer Size?
Dec 17, 2014get some opinions on, or established methods on how your buffer size should be decided.
View 2 Replies View RelatedC :: Two Stumbling Blocks - Determine Size Of Rows To Create In Program
Apr 18, 2014Working on an assignment and I've hit TWO stumbling blocks. I now have to take the first line from a .txt file and use that number to determine the size of rows to create in my program. I am using fscanf but the program hangs. How can I read in this number, store it and use it in a for loop?
The second issue is after reading this number I have to print each number in the .txt file under a different column. (Note that it skips a line after reading the row count.) The .txt file is set up as follows:
9 1 3 6 4 7 8 8 6 1
The output should look sort of like:
Number 1 3 6 4 7 8 8 6 1
Here's my attempt:
#include <stdio.h>
#include <stdlib.h>
#include <conio.h>
#include <math.h>
typedef struct{
int number;
[Code] .......
C++ :: Reads Process And Return Values From It - Application Crashes Because Of Buffer Size
Nov 11, 2014I have an application that reads a process and return values from it. The problem it works fine with small processes but i have some processes that are about 1GB or even 2GB and when i try to read such big processes the application crashes. I'm trying to find a way to read the process memory in chunks of maximum 10 MB. The read code looks like:
Code:
HANDLE hProcess = OpenProcess(PROCESS_QUERY_INFORMATION | PROCESS_VM_READ, FALSE, entry.th32ProcessID);
unsigned char *p = NULL;
MEMORY_BASIC_INFORMATION info;
for (p = NULL; VirtualQueryEx(hProcess, p, &info, sizeof(info)) == sizeof(info); p += info.RegionSize)
[Code] ....
This reads the info.regionsize which can be as large as 100 MB. Is there any way to read it in chunks ?
Visual C++ :: Change Frame Window Size According To Increase In Font Size
Nov 27, 2012Change the frame window size according to font size increases.
View 3 Replies View RelatedVisual C++ :: Text Size In Screen Is Different From Size In Print Preview?
Feb 1, 2013I must take an old MFC project in VC++ 6.0 and make changes.
The problem is text size in screen is different from size in print preview.
for example with this font
Code:
CFont f50;
f50.CreateFont(100,0,0,0,FW_BOLD,0,0,0,DEFAULT_CHARSET,OUT_DEFAULT_PRECIS,
CLIP_DEFAULT_PRECIS,DEFAULT_QUALITY,FF_DONTCARE,"Frutiger LT Std 45 Light");
And this text
Code:
s=_T("Let's try to calculate the size of this text");
and with MM_LOMETRIC map mode
GetTextExtent() returns me:
On screen: (1595,99)
Ink printer + print preview: (1589,100)
PDFCreator + print preview: (1580,100)
comparing with screen size the height is bigger but lenght is smaller. I don't understand.
I can understand that different printers process the fonts in different way and then to have different lenghts. That's not the problem. The problem is I need to simulate in screen the same behaviour i will have on printer because these texts are being aligned in the document, and I don't want to see that the text si aligned different in text than in paper.
What can I do to render the text on screen with the same size I will have on the printer? Print preview is doing it. Should I change the font parameters? is something related with pixels per inch?
Visual C++ :: Draw Buffer With Raw Data?
Nov 19, 2012Got buffer with raw data. How to display it in MFC dialog and refresh it?
View 3 Replies View RelatedVisual C++ :: How To Create Image Buffer In MFC
Jan 27, 2013how to create, initialize, and maintain a memory device context that works as a local buffer for images? The idea is to maintain some large images in local DCs and bitmaps, and only bitblt them to screen in OnDraw().
What I did so far was was to define CDC and CBitmap objects as members of my View class, and then tried to initialize them with the sequence that begins at "// Initialize buffer". I placed that sequence in either OnInitialUpdate, or PreCreateWindow, or OnPrepareDC, or the view constructor, to no avail. The code always crashes in OnDraw, and I've noticed that the m_hDC member of myDevice is zero at that point.
Obviously, the initialization is wrong and MFC does (too many) things in the background which I'm not aware of.... My question was where can I read about that?
Code:
class CMyView : public CScrollView {
// ...
CDC myDevice;
CBitmap bmp;
CBitmap *oldbmp;
[Code] .....
Visual C++ :: Determine Type In Function Template
Jul 28, 2013I want to detect the type in a function template, like this:
template <class myType> myType Function (myType a, myType b) {
//Detect the myType
If (myType is int)
[Code] ......
Is that possible?
Visual C++ :: How To Determine If A Metro App Is Currently Displayed On The Screen
Apr 22, 2014I'm trying to determine (from my Win32 process) if a Metro (or a Modern UI) app is currently displayed on the screen. I found the IAppVisibility::GetAppVisibilityOnMonitor method that can do just that, and I even found a C++ sample, but my issue is that I'm compiling it with the Visual Studio 2008 that does not have the definitions for the IAppVisibility interface, so the following:
Code:
#include <Shobjidl.h> //Earlier version
IAppVisibility* pAppVis = NULL;
HRESULT hr = CoCreateInstance(CLSID_AppVisibility, NULL, CLSCTX_INPROC_SERVER,
IID_IAppVisibility, (void**) &pAppVis);
Results in a set of errors:
Code:
error C2065: 'IAppVisibility' : undeclared identifier
error C2065: 'IID_IAppVisibility' : undeclared identifier
how to define them?
Visual C++ :: Bitmap Display From Buffer Received By TCP Socket
Feb 6, 2013I want to display my image on window without saving it.
When data is received window size changes but there is no display on window.
My Code is:
Code:
int iBufferLength;
int iEnd;
int iSpaceRemaining;
int i;
iBufferLength = iSpaceRemaining = sizeof(chIncomingDataBuffer);
iEnd = 0;
iSpaceRemaining -= iEnd;
[code].....
where I'm doing wrong?
Visual C++ :: Creating A Function That Needs To Determine Perfect Scores
Jun 24, 2013This program is incomplete as I am having difficulty creating the function that needs to find the number of perfect scores entered by the user. I have everything but the function complete ,here is my code:
Code:
// Write a modular program that accepts at least 10 integer test scores from the user and stores them in an array.
// The main should display how many perfect scores were entered (i.e., scores of 100), using a value-returning countPerfect function.
// Input validation: Do not accept scores less than 0 or greater than 100.
#include <iostream>
using namespace std;
int countPerfect(int intArray[], int); // Function prototype
[Code] ....
Visual C++ :: Playing Video Using Windows Media Player From A Buffer?
Oct 25, 2013I am developing a VC++ application with windows media player component. play video from a video buffer data which i have?
View 2 Replies View RelatedVisual C++ :: Access Violation Reading Void Assigned Dynamically Allocated Value Inside Function
Sep 16, 2013Why the void pointer passed to testb doesn't continue pointing to the allocated integer after the function call returns.
Code:
#include <stdio.h>
#include <iostream>
void* testa() {
return new int(1);
[Code] ....
Visual C++ :: How To Determine Cross Platform Type During File Save
Nov 10, 2014I am overriding OnSaveDocument in my MFC document class to strip out the carriage returns when saving my app's document to a UNIX file system but not when the user is saving a file to a Windows file system.
Is there a way to determine if the lpszPathName in OnSaveDocument(LPCTSTR lpszPathName) is a UNIX or Windows file system?
Note, I want to avoid hard coding server names and I want to avoid overriding the FileSave dialog and forcing the user to select Windows or UNIX.
Visual C++ :: Serial Communication In Windows - ClearCommError Finds No Data In Read Buffer
Dec 13, 2013I want to send data from a laptop (windows 7, processor 2.60GHz) to a desktop (windows xp, processor 3.10GHz) using serial communication (using a USB to RS232 convertor). The WriteFile function is able to send the data from the laptop (NumberOfBytesWritten is correct). But on the desktop side, ClearCommError detects no data in the read buffer.
This is the relevant code in my desktop:
while(1) {
ClearCommError(hPort,&dwErrors,&commStatus);
if (commStatus.cbInQue != 0) ReadFile(hPort,&data,1,&dwBytesRead,NULL);
Sleep(10);
}
The if condition is never satisfied. The baudrate and other parameters in the DCB struct are the same on both sides.
The same code works when I write and read in the same system by shorting the RX and TX pins in the RS232 connector.
Visual C++ :: Circular Buffer - No Instance Of Overload Function Matches Argument List
Nov 25, 2014I'm having some issues with my code. For the produce function i am getting an error saying 'no instance of overload function produce() matches the argument list' and also for the lines buffer[head].data = message; buffer[head].time = current_time i get an error saying 'expression must have pointer to object type.
In the code i'm not sure if i passed the variables to the function correctly. I have attached the code .....
code produce.txt
Visual C++ :: Reverse String Sequence In String Buffer
Apr 27, 2013I made a simple little program that takes text from the clipboard, and spits out all the lines I've copied one at a time (so my program can analyze it).
everything works perfectly, except, it spits it own in the wrong order, I want it to spit out from bottom to top. but currently it spits out the data from top to bottom. here is my code :
Code:
#include <iostream>
#include <Windows.h>
#include <string>
#include <sstream>
using namespace std;
int main() {
HANDLE clip; // assigns the var. clip to hold a handle ID.
[Code] .....
I want this loop to run backwards! Like it say's what I want to work backwards. Where as I know how to flip a while loop like this: while(x < 5), how to flip a loop like the one I'm using. how I can do this?
Visual C++ :: How To Add A Limit On Size
Feb 15, 2013Im working on a small code and am trying to limit the size of the mysql databse string its pulling.
It can only be 119 characters, or less if its more i would like to do nothing, but if its meets the requirements it runs the script.
Code:
int32 message_id;
string_t message ="Is requesting some one to respond.";<_______________TEMP SHOULD BE THE POSTERS MESSAGE
string_t username = "Guest";<_______________TEMP SHOULD BE THE POSTERS NAME
// char will not be logged in so get the id manually
[Code] ....
So here is where I'm heaving the problem
if(message is less then 119 characters run script )<<___________THIS IS THE CODE LINE IM TRYING TO LEARN
{
char buf[110];
sprintf(buf,"[Web Chat] %s %s",username.c_str(), message.c_str());
[code].....
Visual C++ :: Histogram With Bin Size 5
Mar 15, 2013I have following code to create histogram, but it gave wrong output. In the program input_vector read 100 double numbers. I want to create a histogram with bin size=5. Output is [0;0;0;0;0].
Code:
vector<double>three_dimensional_shape_retreival_Hough_Transform:: histogram_creation(vector<double> input_vector) {
long int i;
long int j;
Mat histogram_input(input_vector);
cout<<"Histogram Input Matrix:"<<histogram_input<<endl;
int histSize =5;
[Code] .....
Visual C++ :: How To Reduce Size Of Object
Feb 10, 2014I am using Visual C++ to write an app. I write CMyObject class and may allocate a lot of instances of CMyObject object, so I want to reduce the size of CMyObject class.
What I can figure out to do is:
1. I can use the following code to get the accurate size used by a single instance of CMyObject object:
CMyObject Object;
//Get the size of memory allocated for CMyObject object
int nSize = sizeof(Object);
is that correct?
2.To reduce the size of CMyObject, I have several ideas:
(1)Change member function to static member function if it is possible, since each member function will take some spaces in the instance of CMyObject.
(2)Change virtual member function to member function if it is possible, since virtual member function may take more spaces.
(3)Eliminate unnecessary member variables to reduce spaces.
(4)Finally, if (1), (2) and (3) does not work well, then change CMyObject from class to a struct that only contains some member variables, thus will eliminate the spaces allocated for constructor and destructor of a class.
Visual C++ :: Quick Find Window Size
May 18, 2013Somehow I have expanded the "quick find" window in visual c++ 2010 and how to restore it to the original size.
View 2 Replies View RelatedVisual C++ :: Vertical Size / Height Of Control Bar In MDI App?
Jan 28, 2014In a MDI-app with some toolbars and statusbar I created also a controlbar which can be docked to the left side. My problem now: how do I get the exact height of the controlbar?
In CalcDynamicLayout I set the height for the docked state to the height of the mainframe. This value is too big, but it will work basically.
But how can I get the exact height of the controlbar?
